Good morning puggie1995
You can find everything on the subject of ticket refunds here: Ticket refunds | SBB help & contact
If you need a refund for an international trip, it is advisable to call, here are the contact details:
- Contact Center at +41 848 44 66 88 (CHF 0.08/min.) or from abroad at +41 51 225 78 00.
I hope I was able to help you,
Have a great day,
StéphanieB